Systemic Bone Loss and Periodontal Disease: An Updated Review of a Bidirectional Association

Background: Systemic bone loss, particularly osteoporosis, and periodontal disease are highly prevalent chronic conditions that share common risk factors and biological pathways. Increasing evidence suggests a bidirectional relationship between these conditions; however, findings remain heterogeneous and evolving. Objective: This review aims to evaluate and update current evidence on the bidirectional association between systemic bone loss and periodontal disease, with emphasis on underlying mechanisms and clinical implications. Methods: A narrative review of the literature was conducted using major electronic databases, focusing on human studies evaluating the relationship between osteoporosis or systemic bone loss and periodontal disease. Relevant experimental, clinical, and epidemiological studies were included. Results: Most studies support an association between reduced bone mineral density and increased severity of periodontal disease, including greater alveolar bone loss and attachment loss. Conversely, periodontal inflammation may contribute to systemic bone remodeling through inflammatory mediators. However, variability in study design, diagnostic criteria, and confounding factors limits definitive conclusions. Conclusions: Current evidence supports a bidirectional association between systemic bone loss and periodontal disease. Greater interdisciplinary awareness is warranted, and future well-designed longitudinal studies are needed to clarify causality and inform preventive and therapeutic strategies.